Primarily Petroliana Shop Talk Forums Non-Petro Discussions Non-petro Discussion and Showcase 5ft. Silver King Golf Balls Sign - Cleaning Stains

The quick, cheap and easy way to remove rust stains is to use muratic acid and a scrub brush, followed by a rinse with water.
Repeat as needed.

Once you remove as much of the rust stains as possible use some fine WHITE rubbing compound and a buffer, followed by paste wax and a buffer.
You won't get the blue to look good. It's too far gone and the white or grey is showing through.